A method to make bicomponent fibers and articles comprising the same

ABSTRACT

The disclosure generally relates to bicomponent fibers, and more particularly, methods to make bicomponent fibers and articles comprising them, wherein a first extruded component has a moisture level less than a second extruded component. The bicomponent fibers may comprise polyesters and are useful in articles such as carpets and fabrics.

FIELD OF THE INVENTION

The present disclosure generally relates to bicomponent fibers, and more particularly, methods to make bicomponent fibers and articles comprising them.

BACKGROUND OF THE INVENTION

Bicomponent fibers made from the side-by-side spinning of two polyesters are widely used in the textile industry, mainly to impart stretch in the final garment or article. Stretch level can be manipulated through the relative shrinkage of the two polyesters, which can depend in part on the intrinsic viscosity (I.V.) of the two polymers. In the manufacturing process of bicomponent fibers, ideally, polyester starting materials to be used have a desired I.V., and are readily available and inexpensive. When this is not the case, often compromises must be made in the fiber manufacturing process, physical properties of the bicomponent fibers, or both to achieve desired performance characteristics of the bicomponent fibers.

SUMMARY OF THE INVENTION

In a first embodiment, disclosed herein is a method to make bicomponent fibers comprising: a) extruding a first and second component on a spinning machine capable of producing two or more independent melt streams; b) combining the melt streams in a spinneret suited for making bicomponent fibers; c) quenching in air the bicomponent fibers produced in step (b); d) drawing and heat setting the quenched bicomponent fibers; and e) winding up the bicomponent fibers in step (d) by any suitable means; wherein the first extruded component has a moisture level less than the second extruded component.

DETAILED DESCRIPTION OF THE INVENTION

All patents, patent applications, and publications cited are incorporated herein by reference in their entirety.

Ranges and Variants

Where present, all ranges are inclusive and combinable. For example, when a range of “1 to 5” is recited, the recited range should be construed as including ranges “1 to 4”, “1 to 3”, “1-2”, “1-2 & 4-5”, “1-3 & 5”, and the like. As used herein in connection with a numerical value, the term “about” refers to a range of +/- 0.5 of the numerical value, unless the term is otherwise specifically defined in context. For instance, the phrase a “pH value of about 6” refers to pH values of from 5.5 to 6.5, unless the pH value is specifically defined otherwise.

It is intended that every maximum numerical limitation given throughout this Specification includes every lower numerical limitation, as if such lower numerical limitations were expressly written herein. Every minimum numerical limitation given throughout this specification will include every higher numerical limitation, as if such higher numerical limitations were expressly written herein. Every numerical range given throughout this Specification will include every narrower numerical range that falls within such broader numerical range, as if such narrower numerical ranges were all expressly written herein.

Definitions

As used herein, the term “embodiment” or “disclosure” is not meant to be limiting but applies generally to any of the embodiments defined in the claims or described herein. These terms are used interchangeably herein. In this disclosure, a number of terms and abbreviations are used. The following definitions apply unless specifically stated otherwise.

The articles “a”, “an”, and “the” preceding an element or component are intended to be nonrestrictive regarding the number of instances (i.e., occurrences) of the element or component. Therefore “a”, “an”, and “the” should be read to include one or at least one, and the singular word form of the element or component also includes the plural unless the number is obviously meant to be singular.

The term “comprising” means the presence of the stated features, integers, steps, or components as referred to in the claims, but that it does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. The term “comprising” is intended to include embodiments encompassed by the terms “consisting essentially of” and “consisting of”. Similarly, the term “consisting essentially of” is intended to include embodiments encompassed by the term “consisting of”.

The term “bicomponent fiber” as used herein refers to a fiber being comprised of two different polymer components which may be composed of different polymer types, the same polymer type but having different intrinsic viscosities, or blends of two or more polymers. Bicomponent fibers may also be referred to as composite fibers and the terms can be used interchangeably.

The term “BCF” refers to bulk or bulked continuous bicomponent filament. It is essentially one long continuous strand of fiber that is used to make carpet. The terms “bulk” and “bulked” are used interchangeably herein.

The term “carpet” as used herein refers to floor coverings consisting of pile yarns or fibers and a backing system. The may be tufted or woven. As used herein, the term “carpet” encompasses wall-to-wall carpet, carpet tiles, rugs, and mats for vehicles and building entrances, for example those designed to capture foot soil.

The term “face” refers to the side of the carpet containing tufted or woven yarns.

The term “face fiber” as used herein refers to the fiber content of the carpet including that which is visible to the observer. The face fiber is primarily made up of yarns, and those yarns may be styled as cut, loop, cut and loop or any number of styles known to those skilled in the art.

The term “copolymer” refers to a polymer composed of a combination of more than one monomer. Copolymers can form the basis of some manufactured fibers.

The term “crimp” refers to the waviness of a fiber expressed as crimps per unit length. “Crimping” is the process of imparting crimp to filament yarn.

The term “crimp contraction” is a measure of fiber crimp and refers to the contraction in length of a yarn from the fully extended state (i.e., where the filaments are substantially straightened). This is due to the formation of crimp in individual filaments under specified conditions of crimp development. It is expressed as a percentage of the extended length. Crimp contraction can be measured before and/or after treatment of a fiber, for example by heating, to partially or fully develop the crimp; typically the crimp contraction after heating is of more interest and provides more information as it includes the crimp developed by heating. Unless specified otherwise, crimp contraction values disclosed herein are crimp contraction values after heating (Cca).

The term “denier” is a weight-per-unit-length measure of any linear material.

The term “fiber” refers to unit of matter, either natural or synthetic, that forms the basic element of fabrics and other textile structures. It is characterized by having a length at least 1000 times its diameter or width. Typically, textile fibers are units that can be spun into a yarn or made into a fabric by various methods including weaving, knitting, braiding, felting and twisting. Fiber is characterized by its denier (weight in grams per 9000 meters of fiber) and the number of filaments contained in the fiber.

The “filament” refers to a fine thread or continuous strand of fiber. There are two types of filaments: mono-filament and multi-filament. Filaments are characterized by their denier per filament (“dpf”).

The term “homofilament” means that the filament is made from one polymer type.

“Staple” refers to either natural fibers or cut lengths from filaments.

The term “intrinsic viscosity” (“IV”) refers to the ratio of specific viscosity of a solution of a known concentration to the concentration of solute extrapolated to zero concentration.

The term “tufting” refers to a process of creating textiles, such as carpet, on specialized multi-needle machines. A “tuft” is a cluster of soft yarns drawn through a fabric and projecting from the surface in the form of cut yarns or loops. The cut or uncut loops form the face of a tufted or woven carpet.

The term “yarn” refers to a collection of individual filaments, either singly, or plied together with another collection of filaments. The terms “fibers” and “yarns” are used interchangeably herein.

The term “quenching” refers to rapid cooling in water, oil or air to obtain certain physical or material properties.

The term “poly(ethylene terephthalate)” or PET means polymer derived from substantially only ethylene glycol and terephthalic acid (or equivalent, such as dimethyl terephthalate), and is also referred to as polyethylene terephthalate) homopolymer. As used herein, the term “poly(ethylene terephthalate) copolymer” or “co-PET” refers to polymer comprising repeat units derived from ethylene glycol and terephthalic acid (or equivalent) and also containing at least one additional unit derived from an additional monomer, such as isophthalic acid (IPA) or cyclohexanedimethanol (CHDM). Polyethylene terephthalate) copolymer can contain from about 1 mole% to about 30 mole% additional monomer, for example from about 1 mole% to about 15 mole% additional monomer.

The term “poly(butylene terephthalate)” or PBT means polymer derived from substantially only 1, 4-butanediol and terephthalic acid, and is also referred to as poly(butylene terephthalate) homopolymer. As used herein, the term “poly(butylene terephthalate) copolymer refers to polymer comprising repeat units derived from 1, 4-butanediol and terephthalic acid and also containing at least one additional unit derived from an additional monomer, for example a comonomer for PTT copolymers as disclosed herein.

The term “poly(trimethylene terephthalate)” or PTT refers to a polyester made by polymerizing 1, 3-propanediol and terephthalic acid. It is distinguished by its high elastic recovery and resilience. PTT is known to provide stain resistance, static resistance, and improved dyeability. The term “poly(trimethylene terephthalate) homopolymer” means polymer of substantially only 1, 3-propanediol and terephthalic acid (or equivalent). The term “poly(trimethylene terephthalate)” also includes PTT copolymers, by which is meant polymer comprising repeat units derived from 1, 3-propanediol and terephthalic acid (or equivalent) and also containing at least one additional unit derived from an additional monomer.

Examples of PTT copolymers include copolyesters made using 3 or more reactants, each having two ester forming groups. For example, a copoly(trimethylene terephthalate) can be used in which the comonomer used to make the copolyester is selected from the group consisting of linear, cyclic, and branched aliphatic dicarboxylic acids having 4-12 carbon atoms (for example butanedioic acid, pentanedioic acid, hexanedioic acid, dodecanedioic acid, and 1,4-cyclo-hexanedicarboxylic acid); aromatic dicarboxylic acids other than terephthalic acid and having 8-12 carbon atoms (for example isophthalic acid and 2,6-naphthalenedicarboxylic acid); linear, cyclic, and branched aliphatic diols having 2-8 carbon atoms (other than 1,3-propanediol, for example, ethanediol, 1,2-propanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, 2,2-dimethyl-1,3-propanediol, 2-methyl-1,3-propanediol, and 1,4-cyclohexanediol); and aliphatic and aromatic ether glycols having 4-10 carbon atoms (for example, hydroquinone bis(2-hydroxyethyl) ether, or a polyethylene ether) glycol having a molecular weight below about 460, including diethylene ether glycol). The comonomer typically is present in the copolyester at a level in the range of about 0.5 mole% to about 15 mole%, and can be present in amounts up to about 30 mole%.

The term “Triexta” refers to a generic name for PTT, a subclass of polyester. The terms Triexta and PTT can be used interchangeably herein.

Poly(trimethylene terephthalate) has an intrinsic viscosity that typically is about 0.5 deciliters/gram (dl/g) or higher, and typically is about 2 dl/g or less. The poly(trimethylene terephthalate) preferably has an intrinsic viscosity that is about 0.7 dl/g or higher, more preferably 0.8 dl/g or higher, even more preferably 0.9 dl/g or higher, and typically it is about 1.5 dl/g or less, preferably 1.4 dl/g or less, and commercial products presently available have intrinsic viscosities of 1.2 dl/g or less. Poly(trimethylene terephthalates) is commercially available from E. I. du Pont de Nemours and Company, Wilmington, DE under the trademark “Sorona®”.

Carpets made with poly(trimethylene terephthalate) homofibers and manufacture thereof, as well as the fibers and manufacture of the fibers, are described in U.S. Pat. Nos. 5,645,782 Howell et al., 6,109,015 Roark et al. and 6,113,825 Chuah; U.S. Pat. Nos. 6,740,276, 6,576,340, and 6,723,799; WO 99/19557 Scott et al.; H. Modlich, “Experience with Polyesters Fibers in Tufted Articles of Heat-Set Yarns, Chemiefasern/Textilind. 41/93, 786-94 (1991); and H. Chuah, “Corterra Poly(trimethylene terephthalate) – New Polymeric Fiber for Carpets”, The Textile Institute Tifcon ‘96 (1996), all of which are incorporated herein by reference. Staple fibers are primarily used to prepare residential carpets. BCF yarns are used to prepare all types of carpets and are usually preferred for carpets.

Typically, PTT-containing bicomponent fiber is used to make fabrics and apparel having durable stretch attributes. In contrast, such stretch attributes are not needed in the manufacture of carpet. Rather, fibers for use in making carpet are typically mechanically bulked to provide high levels of bulk; such fibers are typically referred to as “BCF” fibers.

Generally

The Applicant has advantageously discovered a method to manufacture bicomponent fibers by controlling the on-line I.V. of the starting polymers which allows one to: optionally use inexpensive polymers in the fiber manufacturing process; and optimize bulk fiber properties while not being limited to the polymer I.V.

The Applicant has also advantageously discovered a method to manufacture bicomponent fibers by controlling the I.V. of the starting polymers off-line.

A method to make bicomponent fibers is disclosed herein.

The method comprises: a) extruding a first and second component on a spinning machine capable of producing two or more independent melt streams; b) combining the melt streams in a spinneret suited for making bicomponent fibers; c) quenching in air the bicomponent fibers produced in step (b); d) drawing and heat setting the quenched bicomponent fibers; and e) winding up the bicomponent fibers in step (d) by any suitable means; wherein the first extruded component has a moisture level less than the second extruded component.

The first and second components of the method disclosed herein may independently comprise a polyester and nylon, and combinations thereof.

The first and second components of the bicomponent fiber may be present in a weight percent ratio ranging from 20:80 to 80:20. The weight percent ratio may be selected from the group consisting of: 20:80, 25:75, 30:70, 35:65, 40:60, 45:55, 50:50, 55:45, 60:40, 65:35, 70:30, 75:25, and 80:20.

The first and second components may independently comprise homopolymers, copolymers, blends, and combinations thereof of polyesters and nylon.

In an embodiment, the first and second components may independently comprise a polyester selected from the group consisting of: poly(trimethylene terephthalate), polyethylene terephthalate), poly(butylene terephthalate), and combinations thereof.

In an embodiment, the polyesters in the bicomponent fibers can be copolyesters, and such copolyesters are included in the meanings of polyethylene terephthalate) and poly(trimethylene terephthalate), provided such variants do not have an adverse effect on the amount of crimp in the entangled yarn or on the fibers’ processing characteristics. For example, a copoly(ethylene terephthalate) can be used in which the comonomer used to make the copolyester is selected from the group consisting of linear, cyclic, and branched aliphatic dicarboxylic acids having 4 to 12 carbon atoms (for example butanedioic acid, pentanedioic acid, hexanedioic acid, dodecanedioic acid, and 1,4-cyclohexanedicarboxylic acid); aromatic dicarboxylic acids other than terephthalic acid and having 8 to 12 carbon atoms (for example isophthalic acid and 2,6-naphthalenedicarboxylic acid); linear, cyclic, and branched aliphatic diols having 3 to 8 carbon atoms (for example 1,3-propane diol, 1,2-propanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, 2,2-dimethyl-1,3-propanediol, 2-methyl-1,3-propanediol, and 1,4-cyclohexanediol); and aliphatic and araliphatic ether glycols having 4 to 10 carbon atoms (for example, hydroquinone bis(2-hydroxyethyl)ether, or a poly(ethyleneether) glycol having a molecular Weight below about 460, including diethyleneether glycol). The comonomer may be present in the copolyester at levels of about 0.5 to about 15 mole percent. Isophthalic acid, pentanedioic acid, hexanedioic acid, 1,3-propane diol, and 1,4-butanediol are typically used because they are readily commercially available and inexpensive. The copolyester(s) may also contain minor amounts of other comonomers. Such other comonomers include but are not limited to 5-sodium-sulfoisophthalate, at a level of about 0.2 to about 5 mole percent. Very small amounts of trifunctional comonomers, for example trimellitic acid, may also be incorporated for viscosity control.

In an embodiment, the first and second components may independently comprise polyethylene terephthalate) (PET) homopolymer or polyethylene terephthalate) copolymer (co-PET), poly(trimethylene) terephthalate (PTT) polymer or a blend of PTT with PET homopolymer or PET copolymer (co-PET).

In an embodiment of the bicomponent fiber, the first component may comprise PTT and the second component may comprise PET, wherein the bicomponent fiber is self-stretching due to differential shrinkage. The first component may comprise PTT having a pellet intrinsic viscosity in the range of about 0.9 dL/g to about 1.25 dL/g and the second component may comprise a mixture of PET pellets having an intrinsic viscosity of about 0.50 dL/g to about 0.80 dL/g, wherein the PET pellets comprise a blend of dried pellets (about 50 ppm moisture level) and undried pellets (about 2500 ppm moisture level).

In an embodiment the moisture level of the undried PET pellets described herein can be in a range from 300 ppm to about 5000 ppm. Examples of the moisture levels of pellets include but are not limited to: 300 ppm, 310 ppm, 320 ppm, 330 ppm, 340 ppm, 350 ppm, 360 ppm, 370 ppm, 380 ppm, 390 ppm, 400 ppm, 410 ppm, 420 ppm, 430 ppm, 440 ppm, 450 ppm, 460 ppm, 470 ppm, 480 ppm, 490 ppm, 500 ppm, 510 ppm, 520 ppm, 530 ppm, 540 ppm, 550 ppm, 560 ppm, 570 ppm, 580 ppm, 590 ppm, 600 ppm, 610 ppm, 620 ppm, 630 ppm, 640 ppm, 650 ppm, 660 ppm, 670 ppm, 680 ppm, 690 ppm, 700 ppm, 710 ppm, 720 ppm, 730 ppm, 740 ppm, 750 ppm, 760 ppm, 770 ppm, 780 ppm, 790 ppm, 800 ppm, 810 ppm, 820 ppm, 830 ppm, 840 ppm, 850 ppm, 860 ppm, 870 ppm, 880 ppm, 890 ppm, 900 ppm, 910 ppm, 920 ppm, 930 ppm, 940 ppm, 950 ppm, 960 ppm, 970 ppm, 980 ppm, 990 ppm, 1000 ppm, 1010 ppm, 1020 ppm, 1030 ppm, 1040 ppm, 1050 ppm, 1060 ppm, 1070 ppm, 1080 ppm, 1090 ppm, 1100 ppm, 1110 ppm, 1120 ppm, 1130 ppm, 1140 ppm, 1150 ppm, 1160 ppm, 1170 ppm, 1180 ppm, 1190 ppm, 1200 ppm, 1210 ppm,1220 ppm, 1230 ppm, 1240 ppm, 1250 ppm, 1260 ppm, 1270 ppm, 1280 ppm, 1290 ppm, 1300 ppm, 1310 ppm, 1320 ppm, 1330 ppm, 1340 ppm, 1350 ppm, 1360 ppm, 1370 ppm, 1380 ppm, 1390 ppm, 1400 ppm, 1410 ppm, 1420 ppm, 1430 ppm, 1440 ppm, 1450 ppm, 1460 ppm, 1470 ppm, 1480 ppm, 1490 ppm, 1500 ppm, 1510 ppm, 1520 ppm, 1530 ppm, 1540 ppm, 1550 ppm, 1560 ppm, 1570 ppm, 1580 ppm, 1590 ppm, 1600 ppm, 1610 ppm, 1620 ppm, 1630 ppm, 1640 ppm, 1650 ppm, 1660 ppm, 1670 ppm, 1680 ppm, 1690 ppm, 1700 ppm, 1710 ppm, 1720 ppm, 1730 ppm, 1740 ppm, 1750 ppm, 1760 ppm, 1770 ppm, 1780 ppm, 1790 ppm, 1800 ppm, 1810 ppm, 1820 ppm, 1830 ppm, 1840 ppm, 1850 ppm, 1860 ppm, 1870 ppm, 1880 ppm, 1890 ppm, 1900 ppm, 1910 ppm, 1920 ppm, 1930 ppm, 1940 ppm, 1950 ppm, 1960 ppm, 1970 ppm, 1980 ppm, 1990 ppm, 2000 ppm, 2010 ppm, 2020 ppm, 2030 ppm, 2040 ppm, 2050 ppm, 2060 ppm, 2070 ppm, 2080 ppm, 2090 ppm, 2100 ppm, 2110 ppm, 2120 ppm, 2130 ppm, 2140 ppm, 2150 ppm, 2160 ppm, 2170 ppm, 2180 ppm, 2190 ppm, 2200 ppm, 2210 ppm, 2220 ppm, 2230 ppm, 2240 ppm, 2250 ppm, 2260 ppm, 2270 ppm, 2280 ppm, 2290 ppm, 2300 ppm, 2310 ppm, 2320 ppm, 2330 ppm, 2340 ppm, 2350 ppm, 2360 ppm, 2370 ppm, 2380 ppm, 2390 ppm, 2400 ppm, 2410 ppm, 2420 ppm, 2430 ppm, 2440 ppm, 2450 ppm, 2460 ppm, 2470 ppm, 2480 ppm, 2490 ppm, 2500 ppm, 2510 ppm, 2520 ppm, 2530 ppm, 2540 ppm, 2550 ppm, 2560 ppm, 2570 ppm, 2580 ppm, 2590 ppm, 2600 ppm, 2610 ppm, 2620 ppm, 2630 ppm, 2640 ppm, 2650 ppm, 2660 ppm, 2670 ppm, 2680 ppm, 2690 ppm, 2700 ppm, 2710 ppm, 2720 ppm, 2730 ppm, 2740 ppm, 2750 ppm, 2760 ppm, 2770 ppm, 2780 ppm, 2790 ppm, 2800 ppm, 2810 ppm, 2820 ppm, 2830 ppm, 2840 ppm, 2850 ppm, 2860 ppm, 2870 ppm, 2880 ppm, 2890 ppm, 2900 ppm, 2910 ppm, 2920 ppm, 2930 ppm, 2940 ppm, 2950 ppm, 2960 ppm, 2970 ppm, 2980 ppm, 2990 ppm, 3000 ppm, 3010 ppm, 3020 ppm, 3030 ppm, 3040 ppm, 3050 ppm, 3060 ppm, 3070 ppm, 3080 ppm, 3090 ppm, 3100 ppm, 3110 ppm, 3120 ppm, 3130 ppm, 3140 ppm, 3150 ppm, 3160 ppm, 3170 ppm, 3180 ppm, 3190 ppm, 3200 ppm, 3210 ppm, 3220 ppm, 3230 ppm, 3240 ppm, 3250 ppm, 3260 ppm, 3270 ppm, 3280 ppm, 3290 ppm, 3300 ppm, 3310 ppm, 3320 ppm, 3330 ppm, 3340 ppm, 3350 ppm, 3360 ppm, 3370 ppm, 3380 ppm, 3390 ppm, 3400 ppm, 3410 ppm, 3420 ppm, 3430 ppm, 3440 ppm, 3450 ppm, 3460 ppm, 3470 ppm, 3480 ppm, 3490 ppm, 3500 ppm, 3510 ppm, 3520 ppm, 3530 ppm, 3540 ppm, 3550 ppm, 3560 ppm, 3570 ppm, 3580 ppm, 3590 ppm, 3600 ppm, 3610 ppm, 3620 ppm, 3630 ppm, 3640 ppm, 3650 ppm, 3660 ppm, 3670 ppm, 3680 ppm, 3690 ppm, 3700 ppm, 3710 ppm, 3720 ppm, 3730 ppm, 3740 ppm, 3750 ppm, 3760 ppm, 3770 ppm, 3780 ppm, 3790 ppm, 3800 ppm, 3810 ppm, 3820 ppm, 3830 ppm, 3840 ppm, 3850 ppm, 3860 ppm, 3870 ppm, 3880 ppm, 3890 ppm, 3900 ppm, 3910 ppm, 3920 ppm, 3930 ppm, 3940 ppm, 3950 ppm, 3960 ppm, 3970 ppm, 3980 ppm, 3990 ppm, 4000 ppm, 4010 ppm, 4020 ppm, 4030 ppm, 4040 ppm, 4050 ppm, 4060 ppm, 4070 ppm, 4080 ppm, 4090 ppm, 4100 ppm, 4110 ppm, 4120 ppm, 4130 ppm, 4140 ppm, 4150 ppm, 4160 ppm, 4170 ppm, 4180 ppm, 4190 ppm, 4200 ppm, 4210 ppm, 4220 ppm, 4230 ppm, 4240 ppm, 4250 ppm, 4260 ppm, 4270 ppm, 4280 ppm, 4290 ppm, 4300 ppm, 4310 ppm, 4320 ppm, 4330 ppm, 4340 ppm, 4350 ppm, 4360 ppm, 4370 ppm, 4380 ppm, 4390 ppm, 4400 ppm, 4410 ppm, 4420 ppm, 4430 ppm, 4440 ppm, 4450 ppm, 4460 ppm, 4470 ppm, 4480 ppm, 4490 ppm, 4500 ppm, 4510 ppm, 4520 ppm, 4530 ppm, 4540 ppm, 4550 ppm, 4560 ppm, 4570 ppm, 4580 ppm, 4590 ppm, 4600 ppm, 4610 ppm, 4620 ppm, 4630 ppm, 4640 ppm, 4650 ppm, 4660 ppm, 4670 ppm, 4680 ppm, 4690 ppm, 4700 ppm, 4710 ppm, 4720 ppm, 4730 ppm, 4740 ppm, 4750 ppm, 4760 ppm, 4770 ppm, 4780 ppm, 4790 ppm, 4800 ppm, 4810 ppm, 4820 ppm, 4830 ppm, 4840 ppm, 4850 ppm, 4860 ppm, 4870 ppm, 4880 ppm, 4890 ppm, 4900 ppm, 4910 ppm, 4920 ppm, 4930 ppm, 4940 ppm, 4950 ppm, 4960 ppm, 4970 ppm, 4980 ppm, 4990 ppm, and 5000 ppm.

The weight ratio between dried and undried pellets may vary between 0 and 100%. Examples of % weight ratios of dried to undried pellets include but are not limited to: 0:100, 5:95, 10:90, 15:85, 20:80, 25:75, 30:70, 35:65, 40:60, 45:55, 50:50, 55:45, 60:40, 65:35, 70:30, 75:25, 80:20, 85:15, 90:10, 95:5, and 100:0.

In an embodiment, one can vary the moisture levels of the undried PET pellets (as described above) in combination with varying the % weight ratios of the dried and undried pellets (as described above) to control the final bulk measurement values (% crimp) of the subsequently formed bicomponent fibers.

In another embodiment of the bicomponent fiber, the first component may comprise PTT and the second component may comprise PET, wherein the first component may have a PTT pellet intrinsic viscosity in the range of about 0.9 dL/g to about 1.25 dL/g and the PTT pellets may be extruded at about 245° C. to 265° C. and the second component may have a PET pellet intrinsic viscosity of about 0.50 dL/g to about 0.80 dL/g and the PET pellets may be undried (about 2500 ppm moisture level), and extruded at a temperature between about 250° C. and 280° C.

In an embodiment the moisture level of the undried PET pellets can be in a range from 300 ppm to about 5000 ppm.

The extrusion temperature used for the undried PET pellets may include but is not limited to 250° C., 255° C., 260° C., 265° C., 270° C., and 280° C.

In an embodiment, one can vary the moisture levels of the undried PET pellets (as described above) in combination with varying the extrusion temperature of the undried PET pellets (as described above) to control the final bulk measurement values (% crimp) of the subsequently formed bicomponent fibers.

In an embodiment of the methods described herein, the PET extruder may be fed with a dried PET pellet supply and with an undried PET pellet supply in a desired ratio as described herein with a difference being that the undried and dried PET pellets are added individually to the extruder rather than pre-mixed.

In an embodiment of the methods described herein, drying conditions of the PET pellet supply hopper can be adjusted to provide the necessary moisture for hydrolysis. For example, PET pellets are typically dried to 50 ppm of moisture during bicomponent manufacturing. By “under-drying” the PET pellets (for examples to 300 ppm moisture), the retained pellet moisture may promote hydrolysis in the extruder to attain a desired lower I.V. In this way, the desired PET IV may be “dialed in” to the spinning process.

In an embodiment of the methods described herein, the PET extruder may be supplied with a vacuum system to control PET I.V. In this way, high IV PET moist pellets with little or no drying can be “trimmed” by the amount of supplied vacuum to achieve a desired I.V.

In an embodiment of the methods described herein, the PET pellets may be dried (ca. 50 ppm) in the manners described herein and small quantities of water can be injected into the heated extruder to affect the desired level of hydrolysis and subsequent I.V. values.

The on-line hydrolysis methods described herein are efficient ways to control I.V. It may be desirable to use the techniques described herein off-line. For example, the hydrolysis methods described herein can be practiced off-line on an extruder not associated with fiber spinning. The hydrolyzed PET exiting the extruder mau have the desired I.V. and then may be re-pelletized. The re-pelletized pellets with the desired I.V. and can then be dried in the usual manner, without the need to control I.V. on-line

Stretch measurement (% crimp) values of the bicomponent fibers made by the methods disclosed herein may be increased a range from about 10% to about 85%. Examples of increased stretch measurement values include but are not limited to 10% 12%, 17%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80% and 85%.

In another embodiment of the bicomponent fiber, the first component may comprise PTT and a second component may comprise PET, wherein the first component may have a PTT pellet intrinsic viscosity in the range of about 0.9 dL/g to about 1.25 dL/g and the PTT pellets may be extruded at 260° C. and a second component may have a PET pellet intrinsic viscosity of about 0.50 dL/g wherein the PET pellets may comprise a blend of dried pellets (about 50 ppm moisture) and undried pellets (about 2500 ppm moisture). The weight ratio between dried and undried pellets may vary between 0 and 20%.

The first and second components may independently be PET or co-PET, and PTT or a blend of PTT with PET or coPET, may be present in the bicomponent fiber in a weight ratio ranging from about 80:20 to about 20:80. For example, the weight ratio of the first and second components may be 80:20, 75:25, 70:30, 65:35, 60:40, 55:45, 50:50, 45:55, 40:60, 35:65, 30:70, 25:75, 20:80, or any ratio within this range.

In an embodiment, Stretch measurement (% crimp) values of the bicomponent fibers made by the methods disclosed herein may not need to be increase but controlled by varying: the moisture levels of an undried component; the ratio of the dried and undried pellets of a component, and/or the extrusion temperature of a particular component. Increasing stretch measurement values as well as controlling them is dependent on the type of polymer(s) used to make a particular bicomponent fiber.

Various additives may be added to one or both polymers of the first and second components. These include, but are not limited to, lubricants, nucleating agents, antioxidants, ultraviolet light stabilizers, pigments, dyes, antistatic agent, soil resists, stain resists, antimicrobial agents, and flame retardants.

Bicomponent fibers may be made by delivering the polymers to a spinneret in the desired volume or weight ratio. While any conventional multicomponent spinning technique may be used, an exemplary spinning apparatus and method for making bicomponent fibers is described in U.S. Pat. No. 5,162,074, to Hills which is incorporated herein by reference in its entirety.

The bicomponent fiber described herein can be in a side-by-side (“S/S”) or an eccentric sheath core (“S/C”) arrangement. The bicomponent fiber can be made in a variety of cross-sectional shapes, for example round, delta, trilobal, scalloped, or other shapes, by using spinnerets specific for each shape, for example as disclosed in U.S. Pat. No. 6,803,102, which is incorporated herein by reference in its entirety.

Also disclosed herein are articles comprising the bicomponent fibers made by the methods described herein. The articles include but are not limited to clothing, fabric, fully drawn yarn (FDY), partially oriented yarn (POY), staple fiber, non-woven fiber, a non-woven fabric, and a carpet.

In an embodiment, a carpet is disclosed herein whose face fiber comprises bicomponent fibers made from the processes disclosed herein.

For use in carpet, the bicomponent fibers disclosed herein can have a denier in the range of about 300 to about 1400 grams/denier. Useful denier per filament can be in the range of from about 2 to about 20.

The bicomponent fibers disclosed herein may be used in conjunction with all other types of fibers, synthetic and natural, used in making carpets. Carpets can be made through mechanical or hand tufting, weaving and hand knotting. Examples include 1) broadloom carpets (also known as wall-to-wall carpets) where a tufted carpet is made in long continuous lengths that are several meters wide for home and commercial applications 2) carpet tiles produced in squares of various sizes for ease of installation 3) rugs for home use or 4) mats for vehicles and building entrances, designed to capture foot soil prior to building entry.

Any method known in the art of preparing carpet from a fiber may be used in preparing the carpets described herein. Typically, the bicomponent fibers disclosed herein can be used in the same carpet manufacturing processes where other synthetic and natural fibers are employed. The bicomponent fiber may be used by itself in carpet fabrication (i.e. as a “singles” yarn) or plied together with more of the same bicomponent fiber or other fiber types (e.g. nylon, polypropylene, polyester) to increase denier. Optionally, the singles and plied fiber may be entangled with an air jet prior to plying and may also be subjected to heat setting by machines specifically designed to thermally set the singles and tufted yarn physical properties.

One example of a heat setting machines suited for this purpose is manufactured by Superba® (Muhouse, France). Whether the bicomponent fibers are optionally air entangled, plied or heat set, the fibers may then be tufted into standard nonwoven or woven backing sheets typical of the carpet industry. The face fiber loops in the tufted carpet may be severed to provide a cut loop carpet. After tufting, adhesive is often applied to the backside of the carpet (i.e. opposite side from the face fiber) to hold the tufts in place. An additional backing layer may also be added to the carpet back side. The adhesive layer may contain fillers or flame retardants, depending on the specific carpet end use. The carpet may then be subjected to dyeing by standard processes common to the carpet fabrication industry; alternatively, pigments may be added during fiber extrusion to the bicomponent fiber and/or to the companion fibers to impart color to the finished fabrics. In addition, the face yarns may be treated with materials designed to impart fire resistance, anti-static properties or stain and soil resistance. The finished carpet is often dried to remove water remaining from the dyeing process.

The manufacturing process described above is typical for broadloom tufted carpets. Variations to this process known in the industry may be employed in the production of rugs, carpet tiles and vehicle mats.

The face fiber comprising bicomponent fiber may have circular or non-circular cross-section, such as trilobal.

EXAMPLES

The disclosure is further defined in the following Examples. It should be understood that Examples, while indicating certain embodiments, are given by way of illustration only. From the above discussion and the Examples, one skilled in the art can ascertain essential characteristics of this disclosure, and without departing from the spirit and scope thereof, can make various changes and modifications to adapt to various uses and conditions.

As used herein, “Comp. Ex.” Means Comparative Example; “Ex.” means Example; “No.” means number; “%” means percent or percentage; “wt%” means weight percent; “IV” means intrinsic viscosity; “dL/g” is deciliters per gram; “g” is gram(s); “mg” is millligram(s); “°C” means degrees Celsius; “°F” means degrees Fahrenheit; “temp” means temperature; “min” is minute(s); “h” is hour(s); “sec” is second(s); “lb” is pound(s); “kg” is kilogram(s); “mm” is millimeter(s); “m” is meter(s); “gpl” is grams per liter; “m/min” is meters per minute; “mol” is mole; “kg” is kilogram(s); “ppm” is parts per million; “wt” is weight; “dpf” is denier per filament; “gpd” or “g/d” is grams per denier; “dtex” means decitex; “dN/tex” means “deciNewton(s) per tex; “mL” means milliliter(s); “IV” means intrinsic viscosity;

Unless otherwise noted, all materials were used as received.

Test Methods

Measurement of Crimp Contraction After Heating (% CCa) - Crimp Contraction Method:

Crimp contraction after heating (%CCa, also known as stretch value) was determined according to the method described herein. The fiber of each Example and Comparative Example was independently formed into a skein of about 5000 +/- 5 total denier (5550 dtex) with a skein reel at a tension of about 0.1 gpd (0.09 dN/tex). The skein was then halved in length by folding the skein in two to accommodate the interior of the oven used for heat setting. The folded skein was hung at its mid-section from a hook and was conditioned at 70 +/- 1° F. (21 +/- 1° C.) and 65 +/- 2% relative humidity for a minimum of 16 hours. The folded skein was then hung substantially vertically on a rack from a hook at its mid-section and a 1.5 mg/den (1.35 mg/dtex) weight was hung through the two loops of the folded skein at the bottom of the skein. The weighted skein was then heated in an oven for 5 min at 250° F. (121° C.) after which the rack and skein were removed and allowed to cool for 5 minutes, then allowed conditioned at 70° F. +/- 1° F. (21 +/- 1° C.) and 65% +/- 2% relative humidity for a minimum of 2 hours with the 1.5 mg/denier weight left on the skein for the remainder of the test. The length of the skein was measured to within 1 mm and recorded as “Ca”. Next, a 1000 g weight was hung from the bottom of the skein, allowed to reach equilibrium and the length of the skein measured within 1 mm and recorded as “La”. Crimp contraction after heating “CCa” value (%) was calculated according to the formula:

%CCa=100 × (La-Ca)/La

Determination of Intrinsic Viscosity

The intrinsic viscosity (IV) was determined using a Viscoteck Y 501 C Forced Flow Viscometer (Malvern Corporation, Houston Texas, USA). A 0.15 g sample was weighed into a 40 mL glass vial containing 30 mL solvent (phenol/1,1,2,2-Tetrachloroethane (60/40 weight percent)) and a stir bar. Sample was then placed into 100° C. preheated heat block, heated and stirred for 30 minutes, removed from the block and cooled for 30-45 minutes before placing into the auto sampler rack of the viscometer. Samples were then analyzed by ASTM method D5225-92 (Standard Test Method for Measuring Solution Viscosity of Polymer with A Differential Viscometer).

Polymer Preparation

Two grades of PTT homopolymer pellets were obtained from E. I du Pont de Nemours and Company, Wilmington, Delaware USA. One grade had an IV of 1.02 dL/g, a second grade had an IV of 0.92 dL/g. PET homopolymer pellets were obtained from Sinopec Shanghai Petrochemical Company, Ltd. Shanghai, PRC and had an IV of 0.50 dl/g. PET copolymer (containing 1.9 mole % isophthalic acid) pellets with an IV of 0.80 dl/g was obtained from NanYa Plastics Corporation, Livingston New Jersey, USA.

In preparation for melt spinning, the PET and PTT pellets were dried under nitrogen in a vacuum oven for 15 hours at 25 inches mercury vacuum and a temperature of 120° C. Under these conditions, both PET and PTT pellet moisture is reduced to about 50 ppm. The dried pellets were transferred directly to the nitrogen-purged feed hopper of the spinning machine. In the examples where a mixture of dried and undried PET pellets are used, the undried pellets were taken directly from the bag and had a residual moisture content of about 2500 ppm.

Fiber Preparation

The first and second components of a bicomponent fiber were melt spun using processes and equipment generally applicable to spinning side-by-side and eccentric sheath/core bicomponent fibers, for example as disclosed in U.S. Pat. No. 6,641,916 B1, U.S. Pat. No. 6,803,102, and US Pat. No. 7,615,173 B2, which are incorporated herein by reference in their entirety.

In spinning the bicomponent fibers of the Examples, the polymers were melted in a pair of Werner & Pfleiderer co-rotating 28-mm twin screw extruders having 0.5-40 pound/hour (0.23-18.1 kg/hour) capacities. One extruder, referred to herein as the East extruder, was used to melt 1) PET pellets dried to about 50 ppm or 2) mixtures of PET pellets wherein some of the pellets were dried to a residual moisture level of about 50 ppm and the remaining pellets were undried and had a residual moisture level of about 2500 ppm. A second extruder, referred to herein as the West extruder, was used to melt PTT pellets dried to about 50 ppm residual moisture. The temperatures of the West extruder, spinning block and East extruder are cited in the Examples. Each extruder fed the spinning block containing a recessed spinneret. The spinneret used was a post-coalescence, side by side, bicomponent spinneret having thirty-four pairs of capillaries arranged in a circle, an internal angle between each pair of capillaries of 30 degrees, a capillary diameter of 0.64 mm, and a capillary length of 4.24 mm.

The bicomponent filaments exiting the spinneret were subjected to cooling by cross-flow quench air nominally at 20° C. and 0.5 mm/sec face velocity. The filaments were then advanced to dual feed rolls operating at about 800-1200 meters/minute, depending on the draw ratio. Between the spinneret and feed rolls, a finish applicator was used to apply lubricant to the filament bundle. The feed rolls were typically heated to 70° C. to affect draw. The filament bundle was then accelerated to the anneal rolls operating at speeds of about 3000-3600 m/min, depending on the desired draw ratio, and the anneal roll temperature was typically 170° C. The annealed bicomponent fiber was then advanced to two sets of dual letdown rolls operating at room temperature, before being wound on a Barmag SW6 600 winder. The fibers had snowman (oblong) cross-sectional shape. The bicomponent fiber in all examples was 75 denier, 34 filament.

Comparative Example A and Examples 1-3 Variation of Pellet Moisture Content

Comparative Example A illustrates a typical manufacturing process for making a PET/PTT bicomponent fiber, wherein 0.50 I.V. PET pellets are dried to about 50 ppm residual moisture and then extruded by the East extruder at 270° C., and 1.02 I.V. PTT pellets are dried to about 50 ppm residual moisture and extruded by the West extruder at 260° C. The ratio of the PET to PTT in the bicomponent fiber is 50/50. The measured stretch value of 48% is in the typical range of commercial bicomponent fibers.

Examples 1 to 3 illustrate the use of on-line hydrolysis to control the amount of fiber stretch produced in bicomponent fibers, using 0.80 I.V. PET. In Examples 1 to 3, 1.02 IV PTT was dried to about 50 ppm and extruded at the temperatures indicated. The only variable in these examples was the amount of undried PET (ca. 2500 ppm residual moisture) mixed in with the dried PET. As is evident in Example 1, drying 0.80 IV to the same level as PTT (e.g. 50 ppm moisture) results in a fiber with almost no stretch. The relatively small difference in pellet I.V. between the PET and PTT does not promote fiber differential shrinkage or percent stretch. In Example 2, the ratio of undried to dried PET pellets was 10/90 weight percent. Under these process condition, the residual moisture in the undried polymer promotes hydrolysis of the 0.80 I.V. PET in the heated extruder. The effect of hydrolysis can be seen by the decrease in pack pressure from 950 psi to 370 psi. This decrease in pack pressure correlates with decreased polymer melt viscosity, decreased polymer molecular weight, increased differential shrinkage and increased fiber stretch. Examples shows the effect of increasing the undried to dried PET ratio to 20/80 weight percent, where the additional residual moisture further promotes decreased pack pressure and melt viscosity and increased differential shrinkage and percent stretch.

TABLE 1 Process Conditions and Stretch Values for Comparative Example A and Examples 1 to 3 Item PTT IV (dried to ca. 50 ppm H20) PET IV (dried to ca. 50 ppm H20) Percent undried PET pellets (ca. 2500 ppm H20) mixed with dried PET pellets West/Block/East Temperature, °c Pack Pressure, p.s.i., West/East DR Bulk measurement (%CP) Comparative Example A 1.02 0.50 0 260/260/270 700/280 2.5 48.0 Example 1 1.02 0.80 0 265/265/270 490/950 2.8 1.9 Example 2 1.02 0.80 10 265/265/270 510/370 2.8 27.0 Example 3 1.02 0.80 20 265/265/270 490/190 2.8 40.4

Examples 4-7 Variation of Extrusion Temperature

Examples 4-7 illustrate the use of on-line hydrolysis to control the amount of fiber stretch produced in bicomponent fibers, by varying the temperature at which hydrolysis occurs in the PET Extruder. In Examples 4-7, 0.92 IV PTT was dried to about 50 ppm and 0.80 IV PET was 100% undried (i.e. ca. 2500 ppm residual moisture). The polymer ratio between PET and PTT in the fiber was 70/30 weight percent. Rather than affect hydrolysis by the concentration of undried pellets, the extent of hydrolysis was controlled by PET extruder temperature. Hydrolysis is a chemical reaction between the polyester and residual moisture and the extent of reaction increases as extrusion temperature increases. In Example 4, the PET extruder was set at 250 C. At this relatively low temperature, little hydrolysis occurs, pack pressure is high, molecular weight remains high, little fiber differential shrinkage occurs and fiber stretch level is low (10.8%). In Example 5, the PET extruder temperature is increased 10° C. to 260° C. At this higher extruder temperature hydrolysis increases, the pack pressure decreases, molecular weight is reduced, fiber differential stretch increases and fiber stretch increased to 22%. Comparison of Examples 4 and 5 shows that increasing the PET 10° C. more than doubles fiber stretch. Examples 6 and 7 show that increasing the PET extruder to 270° C. and 280° C. increases the stretch measurement to 27.2% and 50.5%, respectively. These examples show the important role of extrusion temperature on extent of hydrolysis and fiber properties.

TABLE 2 Process Conditions and Stretch Values for Examples 4 to 7 Item PTT IV (dried to ca. 50 ppm H20) Undried PET IV (ca. 2500 ppm H20) West/Block/East Temperature, °C Pack Pressure West/East, psi Draw Ratio Bulk measurement (%CP) Example 4 0.92 0.80 250/250/250 420/850 2.8 10.8 Example 5 0.92 0.80 250/250/260 430/500 2.8 22.0 Example 6 0.92 0.80 250/250/270 430/380 2.8 27.2 Example 7 0.92 0.80 250/250/280 430/90 2.8 50.5

Example 8-10 Stretch Formation

Examples 8-10 illustrate the use of on-line hydrolysis to produce bicomponent fibers with higher stretch values than obtainable by traditional means. The 0.50 I.V. PET preferred by PET/PTT bicomponent fiber manufactures is typically the lowest IV PET that can be commercially produced, due to difficultly in pelletizing low IV PET. As there is a desire to increase stretch to levels greater than typically available with 0.50 IV PET, lowering the PET IV by hydrolysis is an option. Example 8 shows the process and results for a 50/50 weight ratio PET/PTT bicomponent fiber made with fully dried (ca. 50 ppm residual moisture) 0.50 I.V. PET and 1.02 IV PTT. Examples 9 and 10 show the stretch results for fibers made by mixing the dried PET with 5% and 10% undried 0.50 I.V. PET (ca. 2500 ppm residual moisture), respectively. The stretch values of 65.8% and 69.3% are considerably higher than commercially available fibers. In these Examples, the additional residual moisture further promotes decreased pack pressure and melt viscosity and increased differential shrinkage and percent stretch.

TABLE 3 Process Conditions and Stretch Values for Examples 9 to 11 Item PTT IV (dried to ca. 50 ppm H20) Undried PET IV (ca. 2500 ppm H20) Percent undried 0.50 IV PET pellets mixed with dried pellets West/Block/East Temperature, °C Pack Pressure West/East, psi Draw Ratio Bulk measurement (%CP) Example 8 1.02 0.50 0 260/260/270 710/280 2.8 54.3 Example 9 1.02 0.50 5 260/260/270 740/170 2.8 65.8 Example 10 1.02 0.50 10 260/260/270 710/120 2.8 69.3 

What is claimed is:
 1. A method to make bicomponent fibers comprising: a) extruding a first and second component on a spinning machine capable of producing two or more independent melt streams; b) combining the melt streams in a spinneret suited for making bicomponent fibers; c) quenching in air the bicomponent fibers produced in step (b); d) drawing and heat setting the quenched bicomponent fibers; and e) winding up the bicomponent fibers in step (d) by any suitable means; wherein the first extruded component has a moisture level less than the second extruded component.
 2. The method according to claim 1, wherein the first and second component is independently selected from the group consisting of: polyesters, nylons, and combinations thereof.
 3. The method according to any one of claims 1-2, wherein the first and second component is a polyester independently selected from the group consisting of: poly(trimethylene terephthalate), poly(ethylene terephthalate), poly(butylene terephthalate), and copolymers thereof and the second component is a polyester selected from the group consisting of: poly(trimethylene terephthalate), poly(ethylene terephthalate), poly(butylene terephthalate), and copolymers thereof.
 4. The method according to any one of claims 1-3, wherein the first component is poly(ethylene terephthalate) and the second component is poly(trimethylene terephthalate).
 5. The method according to any one of claims 1-4, wherein the first component has moisture level in a range from about 10% to about 20% and the second component has a moisture level in a range from about 90% to about
 80. 6. The method according to any one of claims 1-5, wherein the first component has a moisture level of about 50 ppm or less and the second component has a moisture level greater than about 50 ppm.
 7. The method according to claim 1, wherein a stretch measurement of the bicomponent fibers produced in step (e) increased in a range from about 10% to about 85% as compared to bicomponent fibers made by steps (a) to (e) wherein the first extruded component did not have a moisture level less than the moisture level of the second extruded component.
 8. The method according to claim 7, wherein the stretch measurement increase is selected from the group consisting of: 12%, 17%, and 40%.
 9. The method according to claim 1, wherein the first and second components of the bicomponent fiber are present in a weight percent ratio ranging from 20:80 to 80:20.
 10. The method according to claim 1, wherein the bicomponent fiber is in a configuration selected from the group consisting of: side-by-side, eccentric sheath core configuration, and trilobal.
 11. The method according to claim 11, wherein the crimp contraction after heating of the bicomponent fiber, of step (e), is in a range from about 10% to about 85% as determined according to the Crimp Contraction Method.
 12. The method of claim 1, wherein an extruder temperature of one of the components in step (a) is in a range from about 240° C. to about 320° C.
 13. The method according to claim 12, wherein an extruder temperature of one of the two extruded components in step (a) is selected from the group consisting of: 260° C., 270° C., 280° C., 290° C., 300° C., 310° C., and 320° C.
 14. An article of clothing comprising bicomponent fibers made by the method of claim
 1. 15. A fabric comprising bicomponent fibers made by the method of claim
 1. 16. A fully drawn yarn comprising bicomponent fibers made by the method of claim
 1. 17. A partially oriented yarn comprising bicomponent fibers made by the method of claim
 1. 18. A staple fiber comprising bicomponent fibers made by the method of claim
 1. 19. A carpet whose face fiber comprises bicomponent fibers made from the method of claim
 1. 20. The carpet of claim 19, wherein the bicomponent fiber is in a configuration selected from the group consisting of: side-by-side, eccentric sheath core configuration, and trilobal.
 21. The carpet of claim 20, wherein the face fiber further comprises at least one additional fiber selected from the group consisting of: bulked continuous filament, synthetic staple fiber, and natural fiber.
 22. The carpet of claim 21, wherein the at least one additional fiber is bulked continuous filament, and the bulked continuous filament comprises nylon, polypropylene, or polyester.
 23. The carpet of claim 21, wherein the at least one additional fiber is synthetic staple fiber, and the synthetic staple fiber comprises nylon or polyester.
 24. The carpet of claim 21, wherein the at least one additional fiber is natural fiber, and the natural fiber comprises wool, silk, or cotton.
 25. A non-woven fiber comprising bicomponent fibers made by the method of claim
 1. 26. A non-woven fabric comprising bicomponent fibers made by the method of claim
 1. 